The present invention relates to article handling systems and methods and more particularly to a system and method for article extraction which provides a decrease in cost and an increase throughput efficiency over related prior art systems. As used throughout the application, articles refer to mail items, magazines, books and other such flat items. It is however within the scope of the present invention that other articles, as would be imagined by one skilled in the art, may be included in the definition of articles.
There are typically three main steps in article sorting: article singulation, article transportation to separate out output bins corresponding to appropriate destination addresses, and article extraction from the output bins to other devices for further handling. Such further handling may include polywrapping, re and/or further sorting, and other handling. The present invention is an improvement in the area of article extraction. However, in order to appreciate the scope of the present invention it is necessary to analyse the entire system and method employed in achieving the above mentioned advantages. To this end, a brief look at prior art systems and methods for article handling is useful.
FIG. 1 depicts a Pocket Sorter system which provides for simple merging with manual and/or DPS mail, the possibility of any kind of packaging at the end, and a simple sorting algorithm. This design's disadvantages include a tremendous number of active and controlled pockets, the necessity for an article sequencing process, and a short time window because of the late arrival time of sequenced articles. In operation, articles 10 arrive from an external feeder and scanner (depicted by arrow 12) into select individual pockets 14. The articles are then sorted into appropriate sections 16 of collection belt 18. Belt 18 is an endless loop about two rotating means 11 facilitating belt movement in the direction indicated by arrow 11. Provision is made for manual sorting 13 of articles on the belt 18 as well. The articles 10 are polywrapped 15 and stacked in a tray 17 for further processing.
FIGS. 2a and 2b depict a flat bed sorter arrangement which provides lower throughput performance per loading point, simple automatic emptying and packaging with mail compressing, and no need for autonomous vehicle technology because of the flat bed pockets. Disadvantages of the flat bed sorter include one shuttle loading point for each level of casing sections, greater length of shuttle track system in the casing sections, and existing impact of mail mix-grade and volume conditions on throughput. In operation, articles are introduced at respective feeders 20, 22 and transported 24 to endless sectioned (26) belts 28 which receive the articles 21 and stack them into trays 23. The design has a width (25) of about 23 meters and the belts are spaced about 150 mm apart.
The transporting of cartridges and/or articles is also disclosed in the prior art as exemplified by U.S. Pat. No. 6,135,697. FIG. 3 depicts a transport system 30 comprising a robotic arm 32 travelling along track 34 for affecting delivery of cartridge(s) 36 and/or articles 38 to appropriate compartments 31. The transport system 30 comprises a sorter 33 and autofeeder 35. The autofeeder 35 has several components including a feeding station 37, jogging edging station 39, queuing station 40, and docking station 42. Positioned atop the docketing station is a cartridge 36 filled with articles 38. The robotic arm 32 is used to relocate the cartridge 36 to a select compartment 31 of compartment array 44. The robotic arm 32 travels along a track 34 running parallel to the compartment array 31. As may be required, a buffer shelf 46 is included having a plurality of buffer compartments 48 arranged in an array 41.
The prior art systems rely upon a same device or combination of devices to both load and extract articles and/or cartridges from their respective storage areas. The device(s) must serve each storage area individually. Such loading and extraction processes are expensive and present engineering challenges. These and other burdens carry over into subsequent processes for article handling, including polywrapping, refeeding and the like.